Universal connection for electric service cords



Sept. 15, 1953 R. M. cHRlsTNE-.R 2,652,546

4 UNIVERSAL CONNECTION FOR ELECTRIC SERVICE CORUS Filed June 11, 1949 IN VEN TOR.

ATTORNEYS.

ROBERT MGHRISTNER.

Patented Sept. 15, 1953 UNITED STATES PATENT OFFICE UNIVERSAL CONNECTION FOR ELECTRIC SERVICE CORDS 4 Claims. 1

This invention is for a universal swivel for use in connection with electric service cords for electric appliances and equipment.

My invention has for its objects to provide a connector for use in electric service cords which will swivel or turn easily, being rotatable through a full 360, and in addition tilt or rock through a wide angle, providing both a swivel and a universal or angular motion. The invention has for its further objects to provide a device of this character, which, while freely movable, will be safe, non-arcing, capable of carrying heavy currents, and relatively inexpensive to manufacture.

Devices oi the kind to which the present invention pertains are especially useful in connection with the service cords of portable or movable electrical appliances and equipment or lights, and are for the purpose of preventing the cord. from becoming twisted and knotted, or protect it from being repeatedly sharply ilexed where it joins the appliance or equipment or another cord.

l'n the present application, I have specically shown one embodiment of my invention designed for use as a connection for two electric service cords, or for use in plugging a service cord into a convenience outlet, but it will be understood that this is by way of illustration and that the invention may be built into electrical appliances such as irons, vacuum cleaners, portable tools or the like, as may be required.

My invention may be more fully understood by reference to the accompanying drawings wherein the device is illustrated on a scale somewhat larger than is actually required, and wherein:

Fig. l is a side elevation of the universal swivel connector ci my invention;

Fig. 2 is a longitudinal vertical section therethrough; and

Fig. 3 is a similar section with one of the parts tilted toward the extreme limit of its angular range oi movement.

The connector is comprised of two relatively movable main parts, one of which is roughly round or spherical and will be designated the ball member. The ball member is designated generally as 2. IThe other main member embraces the ball member and is herein called the socket member. lt is designated 3.

The ball member 2 comprises a body of insulating material, such for example as molded plastic, hard rubber or the like, having a generally spherical head ll and a projection 5. The inner end face of the head or ball portion is cut off square, and there is a circular cavity 6 therein that extends inwardly beyond the center oi the head. The diameter of the cavity is preferably greater than the radius of the ball.

The bottom of the cavity is countersunk, as indicated at l, leaving a shoulder 8 at the bottom of the cavity. Two openings, 9 and Ill, extend from the countersink l to the end of the projection 5, these openings preferably being located symmetrically on each side of the center line of the projection and having the distance between them corresponding to the standard distance for connector blades of the ordinary appliance cord lil.

Secured to the shoulder 8 adjacent the opening 9 is a metal contact strip ll which is Secured in place by a screw l2, the same screw also holding in place a metal strip I3 having a small metal cup lll at its inner end.

There is also Secured to the Shoulder 8 a second contact strip l5 that extends into the opening lil, the strip having an oiset I6 therein to permit it to seat on the shoulder, there being a screw il' for securing it in place. The strip has a portion i8 that extends down along the wall of the cavity and it has a rounded terminal i9 that projects beyond the end of the ball, the strip it being slightly curved, as shown, just above the terminal.

The socket element of the device comprises a molded plastic or other appropriate sleeve or like body 2li having a cylindrical interior. It is here shown as a sleeve, but if formed as a part oi an appliance, as for example an electric iron, it would possibly take other form. The sleeve has an inturned lip 2l at the tcp. Below this lip is a ball race with balls 22, the ball race in turn resting on a ber ring 23. The opening defined by the lip 2i is less than the diameter of the ball,` so that assembly of this particular form is made` by iirst inserting the ball race and balls, then in-I serting the ball member through the bottom end.v

of the Sleeve before the sleeve is closed at the; bottom.

After the parts have been thus assembled, a. hemispherical metal cup or shell 2li is inserted, this shell bearing against the ber ring 23. rthe shell has a central opening in its bottom at 25.,

rlhe sleeve 2t at the end opposite the lip 2i has an internal shoulder 2G. A plastic or other insulating base 2i in the form of a disk is pressed in against this shoulder. It has a central pillar or post 2t that extends through the hole 25 in the metal shell up into the cavity 6. It is molded or otherwise formed with a metal post 29 therein, this metal post projecting beyond the post 28 and having an exposed terminal Si) at its top, This terminal is at the center of the ball element 2, and it presses against the little contact cup lli,

the strip I3 being somewhat resilient. The post 29 has a conductor here shown as a contact blade 3I that extends beyond the base.

The base is also provided with a resilient metal contact element 32 that is molded into it, and which has a contact portion such as blade 33 at its outer end, the blades 3| and 33 being spaced to fit a standard receptacle. The element 32 presses against the metal shell 24 to make a good electrical contact therewith.

The base is held in place by a split Wire ring 34, in an annular internal recess in the sleeve 20, but it may be cemented or fused in place if desired, or some other assembly may be provided.

When the parts are thus assembled, one' electric current path is through blade' 3I; post 29, terminal 3G, contact I4, conductor I 3, to blade I I. The other current path is through blade 33', conductor 32, shell 24, terminal I9, whichy is'Y resiliently pressed against the interior of the shell, conductor I8 and blade orstrip I5.

As thus constructed' the device may be easily manufactured and assembled. The parts freely rotate axially with respect to one another, and in addition relative angular movement through an arc of more than 90 is permitted. The ball bearings, while providing for free relative movement are not essential, especially ifv plastic having a hard, smooth surface is employed.

By reason of the positioning of one contact, i. e., the terminal 30 and the member I4 at the center of rotationv and angular movement of the ball and the other contact in the form of a continuous hemispherical cup or shell concentric with the surface of the terminal 30, contact is maintained at every position'to which the parts may be turned or adjusted, and thereis nobreak in the circuit as relative motionoccurs. The device is safe, in that the electrically cf'indu'ctingv parts are allhoused within the insulating body and'no part of the ball element carries anyl exposed conductor.

As hereinbefore indicated. I have shown one embodiment of my invention but the shape* and ing material having an inturned lipfatthe-'topy thereof and having a central pin with acontact terminal at the bottom thereofextendi'ngf up into the socket, a semi-circular metal shell in the socket member through which the -lpin projects' and from which it is insulated, aballmember" made of insulating material in the socket '-havin'gfa ball portion and an extension,etheball portion having a cavity in the end thereof Ainto Whichsaid central pin in the socket projects, the terminal of the pin being at thecenter of the ball portion, the ball portion' being received insaidseniicircular metal shell, the inturned' lip on 'the socket overhangingthe ball'portion to restrain the parts against endwise separationthefcavity of the ball portionbeing provided with ya contact element that rests on'the terminal of 'the pin,` the cavity-of the ball portion" a1so-being 'prof vided at apoint remote-from the center with another contact that bears on'thelinterior' of the metal shell, said'extension of thev ball memberv being provided with openings for'thev reception of contact blades, the openingseach having a conductor therein, `the conductor `in one opening leading-to oneof-saidcontacts in vthe cavity,

4 and the conductor in the other cavity leading to the other Contact in the cavity, and a pair of conductors on the Socket leading to the shell and pin respectively.

2. A universal swivel connector comprising a socket member of cup-like form made of insulating material having an inturned lip at the top thereof and having a central pin with a contact terminal at the bottom thereof extending up into the socket, a semi-circular metal shell in the socket member through which the pin projects and from which it is insulated, a ball member made of insulating material in the socket having ay ball' portion and an extension, the ball portion having a cavity in the end thereof into which said central pinl in the socket projects, the terminal of the pin being at the center of the ball portion, lthe ball portion being received in said semi-circular metal shell, the inturnedv lip on the socket overhanging the ball portion to restrain the parts against endwise separation, the cavity of the ball portion being provided with a contact element that rest on the terminal of the pin, the cavity of the ball portion also being provided at a point remote from the center with another Contact that bears on theinterior of the metal shell, said extension of the ball member being provided with openings for the reception of contact blades, the openings each having a conductor therein, the conductor in one opening leading to one of said cont-acts in the cavity, and the Conductor in the other cavity leading to the other contact in the cavity, a pair of conductors on the socket leading to the shell and pin respectively, and ball bearings between the ball portion and the socket located between the ball portion andthe socket just immediately under said inturned lip.

3. A universal swivel connector for electric circuits comprising a socket member of insulating material having a cylindrical body with an inturned lip portion at one end and having a separate base at the other end which maybe secured in place when the assemblyis otherwise complete, aY ball member of insulating material having a ball portion and a stem portion, the ball portion being of a size that it may be inserted in the socket before the base is in place, but which is too large to pass the inturned lip portion, the stem portion projecting from the socket beyond said inturned lip, a hemispherical conducting shell in the socket member surrounding the inner half of said ball portion, said shell having a central opening therein, the ball portion having an open cavity in the end thereof opposite the extension, said separate vbase having a contact therein which passes up through the opening in said conducting shell to the center of the ball portion, the ball portion having a contact thereon at substantially the center thereof which bears against said last-named contact on the base, the ball portion having another contact remote from` the center 'which bears against the inner surface'of said heinispherical shell, said .base member having another contact which bears against said hemispherical shell, the projection on the ball portion having terminals therein leading to the respective contacts mounted in the ball portion.

4. Avuniversal swivel connector for electric circuitsl comprising a socket member of insulating material formed of two parts, one of which is substantially cylindrical and has an inturned integral flange, and the other of which is a base portion that is separately joined to the first part,

5 a ball member engaged in the socket member having a ball portion and a stem portion, the ball portion being of a diameter such that the flange on the socket member will restrain the ball portion from being Withdrawn through the socket member past said ange, the projection on the ball portion extending outwardly away from the socket member, said ball portion having a cavity therein opposite said extension, a substantially hemispherical metal shell in the socket member surrounding the inner end of said ball portion and in which the ball portion has a Working fit, the ball portion having a contact thereon which bears against the inner surface of the shell, the shell having a central opening therein, the base part of the socket having a projection thereon which passes through the opening in said shell and in which is a conductor that extends to the center of the ball member, the base member also having a Contact blade that connects with said contact, the base member having another contact blade member that is connected with said shell, the ball member having a Contact at the center thereof which bears against the end of said conductor on the base member, and terminals on the projecting part of the ball member leading to the respective contacts on the ball member.

ROBERT lVI. CHRISTNER.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 1,431,325 Pedersen Oct. 10, 1922 2,067,617 Sheward July 9, 1935 2,104,198 Jones Jan. 4, 1938 2,181,145 Mose Nov. 28, 1939 FOREIGN PATENTS Number Country Date 111,793 Australia Oct. 24, 1940 317,732 England Aug. 20, 1929 545,514 France Oct. 13, 1922 

